function HDW_getRequest()
{
    http_request = false;
    if (window.XMLHttpRequest) { // Mozilla, Safari,...
       http_request = new XMLHttpRequest();
       if (http_request.overrideMimeType) {
       	// set type accordingly to anticipated content type
          //http_request.overrideMimeType('text/xml');
          http_request.overrideMimeType('text/html');
       }
    } else if (window.ActiveXObject) { // IE
       try {
          http_request = new ActiveXObject("Msxml2.XMLHTTP");
       } catch (e) {
          try {
             http_request = new ActiveXObject("Microsoft.XMLHTTP");
          } catch (e) {}
       }
    }
    if (!http_request) {
       alert('Cannot create XMLHTTP instance');
       return false;
    }
    return http_request;
}
function pingLogin() {
     http_request = HDW_getRequest();   
     http_request.open("GET", "/ASPHDWRegistrationAndLogin/keeploginalive.asp", false);
     http_request.send(null);
     timer=setTimeout("pingLogin()",91000);
}
pingLogin()